This invention pertains to a bus bar stab assembly for a motor control center and more particularly to a stab assembly and an insulated housing for the stab assembly.
Electrical apparatus, such as a motor control center, often has a draw-out type protective device which can be racked-in and racked-out of the control center enclosure to facilitate maintenance, testing and installation. The draw-out protective device, which may be a fusible disconnect switch or a circuit breaker, is typically mounted on a carriage assembly which can be racked-out and put racked-in the control center housing. This requires the making and breaking of contact between the protective device mechanism itself and current carrying conductors in the enclosure. A stab assembly is used to make the connection between the draw-out protective device and the bus bars.
Typical stab connector arrangements are illustrated in U.S. Pat. Nos. 3,778,748 and 4,432,036. The stab assemblies usually have fingers which incorporate springs to make the fingers resilient and to facilitate contact with the bus bars. The use of springs reduces the need for precise alignment of the stab fingers and the bus bars, but the use of springs increases the number of parts required for each stab connector. In a manufacturing operation, it is desirable to reduce the number of parts and to reduce the number of assembly steps required to assemble a completed unit. The reduction of assembly steps and parts reduces the overall labor costs and enables the stab connector to be made more economically. Accordingly, it will be appreciated that it will be highly desirable to provide a stab connector which is easy to assemble and which has a relatively small number of parts.
Accordingly, it is an object of the present invention to provide a bus bar stab assembly for making connection between a draw-out protective device and a bus bar.
Another object of the invention is to provide a bus bar stab assembly which has relatively few parts.
Another object of the invention is to provide a stab assembly which can be easily assembled.